SU966807A1

SU966807A1 - Method of protective disconnection of electric installation in case of damage of earthing circuit

Info

Publication number: SU966807A1
Application number: SU802953632A
Authority: SU
Inventors: Виктор Александрович Бунько; Вячеслав Леонидович Кожевников; Сергей Павлович Брылев
Original assignee: Днепропетровский Ордена Трудового Красного Знамени Горный Институт Им.Артема
Priority date: 1980-07-11
Filing date: 1980-07-11
Publication date: 1982-10-15

Description

Изобретение относится к средствам 'обеспечения электробезопасности потребителей электроэнергии на открытых горных работах, в шахтах и строительстве.The invention relates to means for ensuring electrical safety of electricity consumers in open cast mining, in mines and in construction.

Известен ряд способов и устройств предназначенных для защитного отклюм чения при неисправности заземляющей цепи подвижной электроустановки, не имеющей местного заземления.A number of methods and devices are known for protective shutdown in case of a malfunction of the grounding circuit of a mobile electrical installation without local grounding.

Известны системы с использованием в качестве источника оперативного ^сигнала составляющей Нулевой последовательности силового напряжения сети переменного Tokatl ]‘,с использованием 'В качестве источника оперативного тока переменной составляющей постоянного тока после выпрямления[2]^ использованием в качестве источника оперативного тока специального генератора (3}с использованием в качестве источника оперативного сигнала фазного напряжения сети с глухозаземленной нейтралыо(4].There are known systems using the source of the operational ^ signal of the component of the Zero sequence of the power voltage of the alternating current network Tokatl] ', using' As the source of the operating current of the variable component of the direct current after rectification [2] ^ using a special generator as the source of operational current (3} using as a source of an operational signal a phase voltage of a network with a grounded neutral (4].

Наиболее близким к предлагаемому является способ, реализованный в ' устройстве автоматического контроля непрерывности заземляющей сети карье- . ра, состоящий из источника оператив⁵ ного выпрямленного напряжения, па- ; раллельно которому включен шунт, при.соединенный одним зажимом к корпусу распределительного устройства, а другим - к шинопроводу, изолированному ¹⁰ от корпуса распределительного устройства. Шинопровод присоединен к центральному заземлителю,а отходящие, заземлительные магистрали - к шинопроводу. Приемник оперативного сигнала устанавливаются на каждой передвижной рабочей машине, а параллельно входу каждого приемника между корпусом рабочей машины и зазем20 ляющей жилой кабеля включен фильтр, :состоящий из батареи неполярных кон- . денсаторов.Closest to the proposed is a method implemented in a device for automatic monitoring of the continuity of the grounding network of the quarry. RA, consisting of a source of operational ⁵ rectified voltage, pa-; parallel to which a shunt is connected, connected with one clamp to the switchgear housing, and the other to the busbar, isolated ¹⁰ from the switchgear housing. The busbar is connected to the central ground electrode, and the outgoing, grounding lines are connected to the busbar. The operational signal receiver is installed on each mobile working machine, and a filter is included parallel to the input of each receiver between the working machine case and the grounding cable, consisting of a non-polar battery. densators.

Способ контроля исправности заземляющей цепи и защитного отключе3 , 966807 4 ния, реализованный в этом устройстве, заключается в том, что постоянное оперативное напряжение вводится в. контур, включающий шунт, шинопровод, заземляющую .магистраль,корпус_: приклю- § нательного пункта, экран кабеля, корпус передвижной рабочей машины, землю и центральный заземлитель. В результате в контуре возникает оперативный ток, сигнал которого выводит- . 10 ся посредством одного из чувствительных элементов, измеряется и контроли-. руется первым пороговым устройством.The method of monitoring the health of the grounding circuit and the protective disconnection 3, 966807 4, implemented in this device, is that a constant operating voltage is introduced into. circuit, including a shunt, busbar, grounding. highway, housing _: § connecting point, cable screen, mobile working machine housing, earth and central grounding conductor. As a result, an operational current arises in the circuit, the signal of which outputs -. 10 through one of the sensitive elements, it is measured and controlled. It is the first threshold device.

Переменное оперативное напряжение вводится с помощью трансформатора в . 15 контур, включающий’ экранную оболочку: кабеля, заземляющую жилу кабеля, фильтр из неполярных конденсаторов, корпус потребителя электроэнергии и конденсатор фильтра приемника. Сиг- ₂о нал переменного оперативного токавыводится из этого контура с помощью второго чувствительного элемента, измеряется и контролируется вторым пороговым устройством. 25An alternating operational voltage is introduced using transformer c. 15 circuit, including 'screen sheath: cable, grounding cable core, filter made of non-polar capacitors, power consumer housing and receiver filter capacitor. The signal _of the alternating operational current alternating current is derived from this circuit with the help of the second sensing element, it is measured and controlled by the second threshold device. 25

Выходы'пороговых устройств свя- /Outputs of Threshold Communication Devices

Заны с элементами сигнализации и могут быть соединены с цепью отключения силового выключателя, обеспечивая функцию защиты от работы обору- ₂q дования при неисправном заземлении[53»They are equipped with alarm elements and can be connected to the circuit breaker tripping circuit, providing the function of protection against operation of the equipment ₂ q equipment with faulty grounding [53 ”

Данный способ имеет тот же недостаток,. что и . все аналогичные способы и устройства, и заключающийся в прохождении части оперативного тока через Землю, параллельно контролируемой цепи. При этом существенное вНия+ ние на результат измерения сопротивления оказывает переходное сопротивление корпус-подвижного потребителяземля и корпус приключительного пункта-земля, что не позволяет’судить об исправности самой заземляющей цепи. Кроме того, в данном устройстве в цепь заземления подвижного потребителя включена/емкость, чем прерывается металлическая заземляющая цепь.This method has the same drawback. that and. all similar methods and devices, and consisting in the passage of part of the operational current through the Earth, parallel to the controlled circuit. At the same time, the transition resistance of the case-mobile consumer of the ground and the case of the adventure point-ground have a significant impact on the result of measuring the resistance, which does not allow us to judge the serviceability of the grounding circuit itself. In addition, in this device, a capacitance is included in the grounding circuit of the mobile consumer, which interrupts the metal grounding circuit.

Цель изобретения - повышение точности и надежности защитного отключения электроустановки при неисправ-· 50 ности заземляющей цепи.The purpose of the invention is to increase the accuracy and reliability of the protective shutdown of the electrical installation in case of malfunctioning of the earthing circuit.

Поставленная цель достигается тем, что согласно способу защитного отключения электрической установки при неисправности заземляющей цепи, состоящей из контуров земля-корпус ⁵⁵приключательного пункта-экран силового кабеля-корпус подвижного потребителя-земля и земля-корпус прик пючательного,пункта-заземляющая жила силового кабеля-корпус подвижного потребителя-земля, путем ввода в каждый из контуров соответствующих оперативных ЭДС, создающих контурные .оперативные токи, измерения их величин и сравнения последних с установленными эталонными величинами и формирования сигнала отключения при умень:шении измеренных величин токов ниже соответствующих эталонных величин, _;вводимые оперативные ЭДС принимают однородными и включают их согласно между собой е соотношением величин оперативных ЭДС, пропорциональным ;соотношению сопротивлений экрана и заземляющей жилыThis goal is achieved by the fact that according to the method of protective shutdown of an electrical installation in the event of a grounding circuit malfunction, consisting of ground-to-body ⁵⁵ circuits of an adventure point-power cable screen-moving consumer body-to-ground and ground-to-body ground, point-grounding core of a power cable- the housing of the mobile consumer is ground, by entering into each of the circuits the corresponding operational EMF, creating loop. operational currents, measuring their values and comparing the latter with the established standard nnym values and shaping a trip signal when Ability: shenii measured values of currents below the respective reference _values; the input operative EMFs are assumed to be homogeneous and include them according to each other by the ratio of the values of the operational EMF proportional to the ratio of the resistance of the screen and the grounding conductor

X - X* , - г₃ ’ где - оперативные ЭДС,вводимые соответственно в контуры экрана и заземляющей , жилы*;X - X *, - g ₃ 'where - operational EMF, introduced respectively in the contours of the screen and ground, conductors *;

£3“ сопротивления экрана и;заземляющей жилы.£ 3 “screen resistance; and ground wire.

На чертеже изображено устройство, реализующее предложенный способ.The drawing shows a device that implements the proposed method.

Устройство содержит, корпус 1 прикА рючательного пункта, источники 2 и 3 контурных оперативных ЭДС h и , заземляющая жила и проводящий экран (вспомогательная жила) силового кабеля 4 и 5 ,корпус подвижного потребителя электроэнергии 6, элементы вывода сигналов контурных оперативных токов 7 и 8,блок сравнения сигналов и формирования отключающего воздействия 9 и автоматический выключатель силовой сети 10.The device comprises a housing 1 of an adjacency point, sources 2 and 3 of a contour operational EMF h and, a grounding conductor and a conductive screen (auxiliary conductor) of a power cable 4 and 5, a housing of a mobile consumer of electricity 6, output elements of the signals of the loop operating currents 7 and 8, a unit for comparing signals and generating a tripping effect 9 and a circuit breaker of the power network 10.

Предлагаемый способ осуществляют следующим образом.The proposed method is as follows.

Оперативную ЭДС Ц вводят в контур¹ 'корпус 1 (земля)-проводящий экран 5 “ элемент вывода сигнала 7^jкорпус 6 (земля), а ЭДС - -контур корпус 1 (земля)-заземляющая Лил. ла 4 - элемент вывода сигнала 8 -корпус 6. В общем непрерывном металлическом контуре, состоящем из элементов 2,5,7,8,4 и 3 ЭДС и действуют последовательно и согласно, соответственно дйфференциальному методу ввода оперативных ЭДС. Под воздействием этих ЭДС возникают контурные оперативные точки i₃ и i₃, сигналы которых выделяют элементами вывода 7 и 8 , измеряют и сравнивают последние друг с другом и с ус966807 ' тановленными эталонными величинами в блоке 9. на основании чего получают сигнал состояния заземляющей цепи. При неисправном состоянии этой цепи сигнал с блока 9 вызывает защитное отключение силовой сети потребителя электроэнергии выключатёлем 10. Если при исправном состоянии заземля1ющей сети выполняется условие ⁽¹⁾ где - сопротивление проводящего экрана (вспомогательной жилы) ;Operational EMF C is introduced into the circuit ¹ 'building 1 (ground) -conducting screen 5 "signal output element 7 ^j building 6 (ground), and the EMF - circuit building 1 (ground) - earthing Lil. La 4 - signal output element 8 - housing 6. In a common continuous metal circuit, consisting of elements 2,5,7,8,4 and 3 EMF and act sequentially and according to, respectively, the differential input method of operational EMF. Under the influence of these EMFs, contour operational points i ₃ and i ₃ arise, whose signals are distinguished by output elements 7 and 8, the latter are measured and compared with each other and with established reference values in block 9. Based on this, a ground signal is received. In case of a faulty state of this circuit, the signal from block 9 causes a protective shutdown of the power network of the consumer of electricity by the switch 10. If the condition of the grounding network is in good condition, condition ⁽¹⁾ is fulfilled, where is the resistance of the conductive screen (auxiliary core);

- сопротивление заземляющей жилы силового кабеля, го потенциалы общей точки источников ДДС и общей точки элементов вывода сигналов контурных токов, связанных ^соответственно с корпусами 1 и 6, одинаковы.- the resistance of the grounding conductor of the power cable, the potentials of the common point of the DDS sources and the common point of the output elements of the loop current signals associated with buildings 1 and 6, respectively, are the same.

Вследствие этого контурные тока •а =“1з и составляющая оперативного тока/ответвляющегося в землю,равна нулю при любых значениях переходных сопротивлений корпуса 1 и 5 -земляAs a result of this, the loop currents • а = “1з and the component of the operating current / branching into the ground is equal to zero for any values of the transient resistance of the housing 1 and 5 of the ground

При увеличении сопротивления/2_эили вследствие частичных порывов или πό другим причинам соотношение(1 ) /перестает удовлетворяться, и на ос-, новании сравнения сигналов тока I_а|и 1₉ блок 9 выдает сигнал неисправности заземляющей цепи. Кроме того, сравнением каждого из сигналов опе!ративного тока с заданными эталон- ; ными величинами контролируют и та;Кие варианты неисправности, как про-: !порциональное увеличение сопротивле;нйй проводящего экрана и заземляющей жилы силового кабеля вплоть до бесконечности при их обрыве.With an increase in resistance / 2 _e or due to partial gusts or πό for other reasons, the ratio (1) / ceases to be satisfied, and on the basis of a comparison of the current signals I _a | and 1 _9, block 9 gives a fault signal to the ground circuit. In addition, by comparing each of the operational current signals with the specified reference; the values that are controlled by that; Kie fault options, as a pro:! proportional increase in resistance; a ny conductive screen and a grounding conductor of the power cable up to infinity when they break.

Таким образом,[предлагаемый спо' соб позволяет устранить влияние переходных сопротивлений''корпуса приключательного пункта и подвижного потребителя электроэнергии-земля на величины оперативных токов в контурах заземляющей цепи. В свою очередь это обеспечивает повышение надежности защитного отключения потребителя^ при, неисправностях последней.Thus, [the proposed method allows eliminating the influence of transient resistance ”of the corps of the adventure point and the mobile consumer of electricity-ground on the values of operating currents in the contours of the grounding circuit. In turn, this provides an increase in the reliability of the consumer protective shutdown ^ in case of malfunctions of the latter.

isis

Claims

FIELD OF THE INVENTION The invention relates to means of ensuring electrical safety of electricity consumers in open pit mining, in mines and in construction. There are a number of methods and devices designed for protective disconnection in case of malfunctioning of the grounding: a circuit of a mobile electrical installation that does not have a local ground. The systems are known using as a source of operational; a signal component of the zero sequence of a voltage of the AC network; using the variable component of a direct current as a source of operating current after rectifying 2b; as a source of operating current of a special generator 3} using as the source of the operational signal the phase voltage of the network with a low-grounded neutral 1. The closest to the proposed method is the method implemented ovanny automatic control device earthing continuity career network consisting of a source of operative rectified voltage, which is included in parallel shunt, with compounds of one clip to the body distribution device, and another - to the trunking, insulated from the housing of the switchgear. The bus duct is connected to the central earthing, and the waste, grounding lines are connected to the bus duct. The operational signal receiver is installed on each mobile working machine, and a filter consisting of a battery of non-polar capacitors is inserted parallel to the input of each receiver between the working machine casing and the grounding cable. The method of monitoring the operability of the grounding circuit and the protective disconnection implemented in this device consists in the fact that a constant surge voltage is introduced into the circuit, including the shunt, busbar, for the ground and 10th. highway, body, - adventure point, cable screen, body of the mobile working machine, earth and central earthing. As a result, an operational current arises in the circuit, the signal is outputted by one of the sensing elements, measured and monitored by the first threshold device. The alternating operational voltage is introduced by means of a transformer into a circuit including a cable screen sheath, a cable earth conductor, a filter of non-polarized capacitors, an electrical consumer case, and a receiver capacitor of the receiver. The alternating operational current signal from this circuit, using the second sensing element, is measured and monitored by a second threshold device. The threshold outputs are connected to the alarm elements and can be connected to the circuit breaker disconnecting circuit, providing the function of protecting the equipment from malfunctioning 5J. This method has the same functionality as all the similar methods and devices, and part of the operational current through the earth, parallel to the controlled circuit. At the same time, the transitional resistance of the housing-moving consumer and the housing of the adventure point-to-earth, which does not allow judging the operability of the grounding circuit itself, significantly affects the measurement result of the resistance. In addition, in this device, a vault is connected to the ground circuit of the mobile consumer, thereby interrupting the metal ground circuit. The purpose of the invention is to improve the accuracy and reliability of the protective disconnection of an electrical installation in the event of a malfunction of the grounding circuit. Delivered by the fact that according to the method of protective disconnection of an electrical installation in case of a malfunction of the grounding circuit consisting of ground loops - case of an adventure point - screen of power cable - case of a mobile consumer - earth and ground - case of a plug; point-grounding conductor of a power cable, a mobile consumer-earth housing, by inputting into each of the circuits the corresponding operational EMFs creating the loop operating currents, measuring their values and comparing the latter with the set reference values and generating a trip signal at measured values currents below the corresponding reference values entered operational EMF accept homogeneous and include them according to each other with the ratio of the values of operational EMF proportional to the ratio: with Resistance to e-.srana and earthing conductor. I. - - - A - i. li. , 63 - Z3 where 5, fe - operational EMFs, 1, respectively, inserted into the contours of the screen and the grounding vein .; Tlj, 3 screen resistors: .- and.grounded core. The drawing shows a device that implements the proposed method. The device contains, case 1 prikrulyuchnygry nyWfa, sources 2 and 3, looped operational EMF fe and%, grounding conductor and conductive screen (auxiliary conductor) of power cable and 5 Ikorus of mobile power consumer 6, output elements of looping operational TOKOB 7 and 8, a unit for comparing signals and forming a tripping effect 9 and a circuit breaker of the power network 10. The proposed method is carried out as follows. The operational EMF tj is introduced into the circuit of the housing 1 (the earth-conducting screen 5, the element of the signal output 7, the housing 6 (earth), and the emf - the Pj-circuit housing 1 {earth) - the grounding Li. la C is the output element of the signal 8-body 6 In the general continuous metal, the loop contour consisting of the elements 2,5,7,8, if and 3 EMF e and ta act sequentially and according to, respectively, the differential method of input of the operating EMF. Under the influence of these EMFs, contour overlapping points 1 and ij appear, the signals of which are extracted by the elements of output 7 and 8, are measured and compared to each other and with established reference values in block 9. On the basis of which they receive the signal of grounding circuit . In the event of a malfunction, this circuit signal from block 9 causes a protective disconnection of the power network of the power consumers using the switch 10. If the ground condition of the main network is in good condition where e is the resistance of the screen (auxiliary); 2J is the resistance of the grounding core of the power cable potentials of the common point of the sources of DPT and the common TOMKI of the output elements of the loop current signals, respectively, with cases 1 and 6, are the same. As a result, the contour current iff, and the component of the operational current, вет branched into the ground, is zero for any values of the transient resistance of the housing 1 and 5 earth / t. When the resistance / 2e or 3 increases due to partial pores or other reasons, the ratio (ceases satisfied, and on the basis of a comparison of the current signals I | And I ,, block 9 generates a fault signal of the grounding circuit.In addition, by comparing each of the operating current signals with the given reference values, they also control: , as a proportional increase in the resistance of the conductive screen and the grounding conductor of the power cable up to infinity when they are broken. Thus, the proposed method allows you to eliminate the influence of the pe-i transitional resistances of the body of the adventure point and the mobile power-to-earth mobile the magnitude of the operational currents in the circuit of the grounding circuit. In gray, this ensures an increase in the reliability of the protective disconnection of the consumer, with the latter failing. 07 The invention of the method of protective disconnection of electrical installation in case of malfunction of the grounding circuit, consisting of the contours of the earth - the body of the adventure point - the screen of the power cable ; the earth, by inputting into each of the circuits the corresponding operational EMFs creating the circuit current operating currents, measuring the current values and comparing the latter with the established reference values, and generating a trip signal with decreasing; The measurement of the current values is lower than the corresponding reference values, characterized in that, in order to improve the accuracy and reliability of the protective disconnection, the inputted operative EDs are assumed to be homogeneous and include them according to each other, with the ratio of the OPE values; effective emf proportional to co; the ratio of the resistances of the screen and the earth conductor beyond it, where 6 is the operational emf introduced into the contours of the screen and the ground conductor, respectively; screen and grounding resistances Sources of information taken into account during the examination 1. USSR author's certificate No., cl. G 01 R 27/20, 1972.

2. USSR author's certificate number 376732, cl. G 01 R 27/20, 1971.

3. USSR author's certificate №L51021, cl. G 01 R127 / 20, 1971. i. German patent tf, 2533299, b.i H 02 H 5 L2, 1977. 5- Tonkoshkur l. S., et al. Automatic device for controlling the continuity of a quarry ground network. -, Industrial Energy, 1976, iN.